In recent years, the increasing costs and shortage of heating fuels have initiated great concern regarding the effectiveness of insulation used in homes, cottages, office buildings and the like. Persons occupying these structures are particularly concerned with unusually high heat losses through walls, floors, ceilings, and any other insulated surfaces. However, since the insulation is provided as a backing to the surface, it is highly difficult if not impossible to visually determine locations of poor or no insulation. Furthermore, a "touch" or "feel" method of determining areas of high heat loss is very inaccurate and at best, will only indicate a general area of heat loss. As can be appreciated, this is not adequate since the addition of further insulation requires tearing down and rebuilding of the surface and in order to minimize the amount of wall to be torn down an exact location must be determined.
It would appear that the best method of finding areas of poor or no insulation is to accurately determine the inner wall, ceiling or floor surface temperature at a specific location and to compare that temperature to other accurately measured temperatures for other specific locations on the inner surface of the wall, ceiling or floor. However, this method requires the use of a portable temperature sensing device including temperature sensing means which is isolated from the ambient room temperature for measuring the temperature of a specific location. Presently available thermometers and the like do not have this feature, and any temperature reading provided by them is obviously adversely influenced by surrounding temperatures.
The present invention provides a portable temperature sensing device for measuring the temperature of a specific location on a planar surface while minimizing the thermal effects of surrounding conditions. The device comprises a thermally insulated frame, a thermally conductive heat transfer member extending from the exterior of the frame to a sealed cavity within the frame, a temperature measuring instrument in the cavity in contact with the heat transfer member and means for reading said temperature measuring instrument. The heat transfer member is adapted for intimate contact with a planar surface and the arrangement is such that the heat transfer member is essentially isolated from the thermal effects of the surrounding conditions by the insulated frame when the device is in use.
The invention provides a method of appraising the insulating properties of the material backing a selected area. The device allows the user to determine whether temperature variances exist across the surface and also to compare the temperatures of various different surfaces to determine the surface of greatest heat loss per unit area assuming equal outside conditions.